Reconstruction of C1 lateral mass with an expandable cage in addition to vertebral artery preservation: presenting two cases.

PURPOSE: C1 lateral mass reconstruction is recommended, in cases of instability caused by tumor involvement or extensive C1 lateral mass resection. However, because of the anatomical complexity of the area and, most importantly, the proximity to vertebral arteries, few cases of reconstruction have been reported to date. The purpose of this report is to present technical details of C1 lateral mass reconstruction in conjunction with vertebral artery preservation from a posterior approach. METHODS: Two cases of one stage craniovertebral junction instrumentation and C1 lateral mass reconstruction in conjunction with vertebral artery preservation from a posterior approach are presented. RESULTS: In both cases of extensive resection of lateral mass due to tumor involvement, an expandable cage was used for C1 lateral mass reconstruction, which has been used only in one patient in literature. Complementary pathological examinations of the two cases indicated two rare tumors that had been reported in the upper cervical region so far. The first case became an unknown origin metastatic cancer and the second was reported to be a primary non- Hodgkin lymphoma. CONCLUSIONS: C1 lateral mass reconstruction with an expandable cage together with VA preservation is recommended in cases of extensive C1 lateral mass resection to increase the total strength and to shorten the length of the posterior device and probably better fusion. The expandable cage is preferred because of safer placement under compression instead of the lateral mass.

Traumatic Cervical Vertical Translational Injury: A Case Report.

Traumatic cervical translational injury is a notably rare and highly unstable subtype of type C sub-axial cervical spine injury with high morbidity and mortality rates. Hereby, we report a 41-years-old man who was a case of multiple trauma due to car rollover. He was completely conscious, complaining of cervical pain, with a GCS score of 15/15. His neurological examination was unremarkable. The cervical CT scan revealed a vertical translation at the C6-C7 level (roughly 11 mm) and bilateral facet joint diastases which are highly unstable injuries. A two-stage combined anterior and posterior fixation operation was performed. First, an anterior cervical discectomy and fusion with autologous graft and plate fixation, and then a posterior approach with lateral mass screw fixation was performed. Disruption of the anterior longitudinal ligament, annulus fibrosis, facet capsules, and severe strain of ligamentum flavum was noted intraoperatively. He had no early and late complications within 2 years of follow-up.